(i) Field of the Invention
The present invention relates to a method and system for estimating a visceral fat area. More specifically, it relates to a method and system for estimating a visceral fat area by use of a bioelectrical impedance.
(ii) Description of the Related Art
In recent years, accumulation of visceral fat has been receiving attention as a factor which exerts a significant influence on health and causes the onset of a lifestyle-related disease. An example of means for knowing accumulation of visceral fat is a method for estimating a visceral fat area by means of X-ray CT. However, to practice the method, assistance of a radiological technician is essential due to use of X-rays. This keeps the method from being widely used. Further, the method cannot be said to be favorable in that it causes an subject to be exposed to X-rays. In addition, the method also has a problem that its operation costs are excessively high.
Meanwhile, there is a correlation between a abdominal circumference on a navel and a visceral fat area, and there is a method for estimating a visceral fat area by use of the correlation.
However, a measurement value of the abdominal circumference on the navel is significantly influenced by where the circumference is measured, a degree of tension in the abdominal part, timing of the measurement, i.e., before or after meal, and a condition of an subject such as a position of the subject. Therefore, when a visceral fat area is to be estimated based on only the measurement value or with emphasis on the measurement value, the estimation is liable to be influenced by the above measurement conditions. Further, when an subject tries to measure a abdominal circumference on a navel by himself/herself, the subject is liable to tense his/her abdominal part at the time of the measurement or make the measurement off a proper position.